The difficulty is that it is arguably in the benefit of the "collective", or of society, to reserve the best education for those that will benefit most from it.

On the other hand you have the ideal of "comprehensive" education. It is often argued in support of comprehensives that they allow for everyone to access high standards of education (ideally) and therefore everyone achieves highly, not just those at the top of IQ/innate ability tables.

Someone who favours the "bipartite" system of elite grammar schools and comprehensive schools existing side by side would point out that many comprehensives (mostly, I understand, in inner-city areas) do not have particularly high standards of education.

A proponent of comprehensive schools would point out that comprehensive schools cannot be truly comprehensive if there is an elite alternative in the form of grammar schools or private schools.

In addition there are many comprehensive schools that are surrounded by middle-class families with "sharp elbows" that have bought homes with the strategic purpose of getting their kids into a "good school." These are hardly comprehensive, as poorer families are excluded because they can't afford the houses in an area with good schools.

This issue is also mixed up with ideas of class that are too prevalent in the UK. In somewhere like Germany or Sweden a plumber can look a physician in the eye without all the terrible overtones of class and status that plague us here in the UK.

To get back to the issue of pre-university examinations. I don't know if they are a good idea or not.

That's it.

What - you wanted me to construct some elaborate for/against argument and then plumb down on one side or the other?

I don't know the answer.

Why is it so difficult for journalists, commentators and politicians to admit, just for once, that they don't know?